Needlepunching process

In the case of 6.0-30 denier PP staple fibers for needle felts, the following requirements have to be met for spin and end finishes adjusted fiber-to-fiber friction for drawing good antistatic properties protection against mechanical damage with needlepunch processes one-way spin finish, i.e., the same spin finish for all positions. 

Figure 3.3 Needlepunching process diagram. Source Texel Inc.

Nonwoven geotextiles. Nonwoven fabrics are defined as a sheet, web, or batt of directionally or randomly oriented fibres/filaments, bonded either by friction, and/or cohesion, and/or adhesion. In general, nonwoven fabric formation can be considered as a two-step process web formation (aligning the fibres with certain orientation characteristics) and bonding these fibres by mechanical, thermal, or chemical means. This two-step process has formed the classification of nonwoven structures, i.e. carded, airlaid, spunlaid, meltblown, needlepunched, hydroentangled, adhesive bonded, thermal bonded, stitch bonded, etc. Some of the important processes that are used for the manufacture of nonwoven geotextiles are discussed below. 

Nonwoven Manufacturing. Cotton staple is readily processed to form carded, air laid, or carded/crossed-lapped webs that can be bonded by various techniques to form useful nonwoven materials, eg, needlepunched, spimlaced (hydroentangled), and stitch-bonded nonwovens, and resin-bonded and thermal-bonded carded fabrics (68). Many times a combination of these processes is used to produce hybrid structures and other products. Cotton s share of the nonwovens market in 2002 is 7.8% globally and 2.8% in North America (69). In 2000-2001, 32-36 million kg (70-80 million lb) of cotton was used in North America to... 

Mullen and Koemer (2007) described tests on a multilayered needlepunched nonwoven geotextile composite consisting of layers of different thicknesses and poro-metries to wrap and protect exposed pipelines from damage and sabotage. They are infilled with a shear thickening fluid (STF) which arrests the projectile before penetrating the pipeline. The process is as follows ... 

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